Great Hammerhead Shark
Not to be confused with the Scalloped Hammerhead. |location = Tropical Oceans |diet = }} The '''Great Hammerhead Shark' is a cartilaginous fish that can be adopted in Zoo Tycoon: Marine Mania. Zoopedia Info The great hammerhead shark, or Sphyrna mokarran, is the largest of the nine species of hammerheads. Hammerheads are a distinct group of sharks with a wide, flat, almost rectangular head with eyes at the sides. The great hammerhead is one of the largest of the predatory sharks. The great hammerhead averages eleven feet in length, but has been known to grow up to 20 feet long, weighing anywhere from 500 to 1000 pounds. The first dorsal fin is very tall and pointed. This is the triangular fin associated with sharks by most people. Hammerheads have a second, shorter dorsal fin. Despite being shorter, this fin can still be as long as five percent of the shark’s total body length. The "hammer" of these sharks is clearly their distinguishing feature. The head is often slightly indented in the center of the rectangular hammer, and the head can make up to a quarter of the shark’s total length. This large head can be moved up and down as well as side to side due to specially developed muscles in the head and neck. Besides expanding the shark’s visual range, the hammer-shaped head may be an important part of the shark’s electroreceptive system. Electroreception is the ability of some sharks and a small number of other aquatic animals to detect electrical signals as they travel through the water. Any muscle contraction by any animal creates an electrical signal (including the contractions of a beating heart), and water conducts electricity extremely well. Sharks use small organs called "ampullae of Lorenzini" to detect these electric fields. An ampulla is a pore with a jelly-filled pit below it. Hairless sensory cells in these pits are stimulated by electrical signals and send information about them to the shark’s brain to be processed, along with auditory, visual, and olfactory inputs. There are several uses for this sense. A shark that cannot see or smell can still find a flatfish buried in the mud using this sense. And since this sense is over one hundred times more sensitive than is needed to detect a resting fish, it may also be used for navigation, since the Earth has a magnetic field. Since corroding metal produces weak voltages, sharks sometimes attack metal objects like boats. When not attacking submarines, the great hammerhead shark prefers foods such as sardines, herring, tarpon, jacks, grouper, sea cats, flatfish, and croaker. These large fish will also eat stingrays, skates, and even other sharks. In order to consume a ray, the great hammerhead uses its head to pin the hapless ray down, and then bites off the wings before consuming its prey. Some hammerhead sharks eat so many stingrays they develop immunity to the poison of these creatures, despite having their mouths and jaws continuously stuck with stingers. Hammerhead sharks prefer tropical waters and the warmer of the world’s temperate waters. Many migrate to cooler waters in the summer, returning to the tropics for the winter. The sharks are found in depths up to two hundred and sixty feet, and when far from shore, are often sighted in large schools. Like many sharks, baby hammerheads are born alive. They are viviparous, meaning that the eggs hatch within the mother and the young mature in the uterus before being born. Unlike many other sharks, female hammerheads have both a placenta and an umbilical cord and can thus nourish their young, helping to prevent the rampant cannibalism that occurs in many other shark species. Category:Marine Mania animals Category:Animals Category:Sharks Category:Saltwater animals Category:Aquatic animals Category:Carnivores